How 5G could help transform construction

For Gammon, automating the 3D scanning process in this way generates a major productivity boost. “This is a massive benefit to us: it is a use case we definitely want to explore further,” says Michael O’Connell. “If I have got 50 to 60 scan points that I want to do in a day, I’d send two skilled employees down to the site to do that scanning and it would probably take them the entire day and even then I can’t process anything until they come back.”

Gammon typically conducts laser scanning at three stages during each project. It scans the structural works, the architectural works prior to ceilings installation and as-built status on completion of the job. Each of these stages are used to validate different stages of the project and the captured data is used to update the BIM model. Depending on the size and complexity of the project, between 60 to 120 days could be required to complete these steps.

Even though Gammon does require a human being to watch a scanning robot (to ensure it isn’t stolen), the 5G connectivity speeds up the whole process. In the past, the workers would have returned to the command centre with all the data on the memory card or on the tablet depending which scanner they were using. “Now we’re turning around the data processing quicker and we’re able to make faster decisions,” says Michael O’Connell. “The BCA is looking for between 30-40% productivity benefits and I think we are touching that.”

During the Sentosa trial, Gammon also came across a supplementary benefit. As the robots have onboard cameras, they can use 5G to transmit live images of the site back to the control centre, where image recognition software can detect any safety issues. “With that video feed, we were able to test whether a worker had his safety helmet on or was wearing the right PPE,” says Michael O’Connell. “So you’ve got robotic supervisors that can walk around laser scanning the site and also performing an autonomous monitoring role.”

Being able to employ the robots across multiple use cases further improves the business case for Gammon, enabling it to achieve a quicker return on its investment in both hardware and the broader solution. “I would imagine this would become like a fleet of robots for Gammon, where it’ll be deployed to different project sites to undertake scanning activities at different stages of the project,” Michael O’Connell says.

Gammon says the 5G-connected CC TV is also proving its worth, as it is enabling staff on site to be notified immediately about any safety or operational risks. On most large construction sites, a supervisor is “using his eyeballs to monitor and to track his workers on safety compliance,” notes James Chan Yung Hau, Assistant Director, 5G Ecosystem & Partnerships, Singtel. “But a supervisor can only watch one place at a time. With connected high-resolution cameras, I can run all these different AI algorithms on the same video feed on the edge compute to check for safety equipment, clustering, social distancing, and other potential hazards. The supervisor can be alerted through their mobile computing device, if there are breaches.”

For larger construction projects involving scores of workers, this kind of monitoring could greatly improve safety and ultimately efficiency. Although he can’t yet quantify the benefit, Michael O’Connell expects this system to result in a significant reduction in accidents. As coverage expands, Gammon is likely to deploy 5G connected CC TV on every project it undertakes.

Gammon is also enthusiastic about using augmented reality to visualise the sequence of construction on a digital twin of the site. “The trial that we did on Sentosa was very, very successful,” says Michael O’Connell. “You’re essentially taking an operations team or your safety team and you’re going through the step-by-step installation in the actual location on site, a digital trial run for the upcoming activity. So we will certainly be looking at using that for some of the key risk activities on our new MRT (the mass rapid transit system in Singapore) project.”

Although 5G-connected drones will also make it easier to inspect and monitor construction sites, Michael O’Connell believes this use case will require a longer gestation period. He says it will take time to convince clients that “they can actually conduct these inspections remotely and still maintain control over the inspection. I don’t think we will be able to roll this out for many projects over the next year or two.” In the longer term, the widespread use of drones for inspecting construction is likely to depend on whether they can meet requirements set out by the building control authorities.

“Gammon experimented,” explains James Chan. “But they faced difficulties in terms of latency in transmitting all the video feed back to the command centre. If they don’t have that video feed in real time, the inspectors may have to redo it again. That translates into a loss of productivity. The key thing is the low latency of 5G.”

At the same time, the additional capacity provided by 5G means multiple video analytic use cases can be run off a single CC TV camera. It also allows for the transfer of large cloud point data files generated from the 3D laser scanning. “You need 5G capabilities because of the size of the data you’re dealing with now with some of the BIM models, they’re so detailed,” explains Michael O’Connell. “If you want to use those models for verification of what you’ve built, then you need that 5G capability. If I want to laser scan something and overlay it for the BIM model, I can get a very accurate representation. But if you don’t have the bandwidth or you don’t have the latency, the 3D model tends to drift.”

The initial findings from the Sentosa trial suggest to Gammon it will certainly earn a return on an investment in 5G connectivity on construction sites where the work is above ground. Now it needs to run trials in subterranean environments.

“We’re already thinking of using one or two of these use cases on other projects,” says Michael O’Connell. “We have just started a new project for the MRT (the mass rapid transit system in Singapore). As it is a below ground project, it has a few more challenges in terms of whether there’s sufficient 5G network signal to drive the technology. But that’s one of the reasons why we’d like to test it: we do a wide range of projects, some above ground, some below ground. All of them have their own sort of IT infrastructure challenges to them.”

“Potentially, there are more use cases for 5G on construction sites,” notes Michael O’Connell. “Whatever technology you’re looking at or whatever idea you’re having the biggest constraint was always the network.”

The usage of 5G in construction is likely to be driven by both the potential productivity and safety gains, and building regulations. Regulators may well require large construction sites, for example, to demonstrate digitally that they are meeting specific safety and environmental standards.

As 5G coverage expands and improves, every part of a construction site could be monitored by high definition cameras that could use 5G to deliver a continuous video stream to the command centre. With image recognition software, it would then be feasible to build a very detailed real-time model of the site, which could then be used to verify the quality of the work and compliance with both safety and environmental regulations, for example. The net result would be a highly-detailed digital record of the work, which could then be used to help fix any faults or resolve any disputes.